1. Field of the Invention
The present invention relates to a ratchet wrench. More specifically, the invention relates to a ratchet wrench having a handle with a magnetic extension handle pivotally attached to the wrench handle.
2. Description of the Related Art
Mechanics often find it necessary to install a nut onto or remove a nut from a threaded machine bolt where the nut is located in a confined area which precludes the use of a conventional ratchet wrench. Conventional ratchet wrenches are not suitable for use in such confined areas because of interference with the back and forth action of the ratchet handle or because the mechanic cannot reach the area in such a way as to transmit the necessary torque to the wrench handle to facilitate the installation or removal process. Accordingly, there is a need for a simple and relatively inexpensive ratchet-based tool for extending the user's reach when applying the necessary torque to work on nuts threaded onto machine bolts in confined or recessed areas. This invention provides such a ratchet-based tool.
One improvement, seen in wrenches used for working in confined areas, is to have the driver pivot with respect to the wrench stock. For example, U.S. Pat. No. 662,966 issued to Robertson on Dec. 4, 1900, U.S. Pat. No. 980,632 issued to Hartvigsen on Jan. 3, 1911 and U.S. Pat. No. 1,643,814 issued to Peterson on May 11, 1926 describe wrench stock assemblies which may be positioned in alignment with the longitudinal axis of a nut engaging socket or arranged at an angle to the socket to enable the socket to operate on nuts which are not readily accessible with an ordinary wrench. A cross bar handle is provided to increase available socket torque. However, in either configuration, socket torque in a confined space is limited by the user's ability to rotate the wrench stock about its longitudinal axis. Unlike the Robertson, Hartvigsen or Peterson wrenches, the present invention offers an increased ability to transmit torque to the wrench head in a confined space by taking full advantage of the mechanical lever action offered by a ratchet wrench handle manipulated back and forth by a pivoting T-gripped extension shaft.
Other wrench configurations are known which provide for the exertion of the necessary tightening or losing torque on a nut in a confined space. In U.S. Pat. No. 2,627,330 issued to Gantz on Jul. 3, 1948, the wrench handle is attached to an extension shank. Access to a nut in a confined space is governed by the length of the extension shank. However, because the handle must be rotated about the longitudinal axis of the extended shank to work on the nut, this structure, like many others, presupposes free access for a considerable distance outwardly from the nut in line with the longitudinal axis of the extended shank.
Additionally, U.S. Pat. No. 3,270,597 issued to Neff et al. on Sep. 6, 1966 discloses a locking adjustable angle wrench extension handle. This structure provides an increased ability to work in confined spaces compared to a standard fixed handle wrench. However, the swing of the adjustable angle wrench extension handle during the back and forth ratchet movement may still be restricted unless there is significantly free access along the arc described by the handle's swing.
An additional type of wrench described in the patent literature is the dual action or "speed" wrench. This wrench structure can be used in a first configuration to cause force on the wrench handle to be applied directly to the shank to tighten or loosen nuts. It can also be used in a second configuration wherein the handle can be moved to cause the shank to rotate rapidly to spin the nut on or off a bolt under conditions of lesser load.
For instance, U.S. Pat. No. 5,517,884 issued to Sanders on May 21, 1996 describes a ratchet wrench handle threadedly connected to a handle extension. The wrench handle opposite the head is centrally bored for slidably receiving a rod member hingedly connected with the handle extension permitting the handle extension to be disposed normal to the longitudinal axis of the wrench handle. In this position, the wrench handle can be moved in a rapid fashion under a lesser load condition through a selected arc. However, with the handle extension disposed normal to the longitudinal axis of the wrench handle, this structure presupposes free access for a considerable distance outwardly from the nut in line with the longitudinal axis of the nut.
Similarly, U.S. Pat. No. 5,280,740 issued to Ernst on Jan. 25, 1994 shows a socket wrench with a pivoting socket driver head and a handle that is rotatable about the longitudinal axis of the wrench shaft. In a first position, with the wrench shaft parallel to the socket driver head, the wrench can be used in the same manner as a fixed handle wrench to apply significant torque to the driver head. Additionally, the wrench shaft may be pivoted with respect to the socket driver head to a second position whereby the wrench shaft is parallel to the driver. In this second position, the handle may be used in a cranking manner to spin a nut about a bolt under lesser load conditions. As seen with the Sanders wrench, in the second position, the Ernst structure also presupposes free access for a considerable distance outwardly from the nut in line with the longitudinal axis of the nut.
U.S. Pat. No. 4,406,186 issued to Gummow on Sep. 27, 1983 shows a ratchet wrench with a handle pivot pin mounted on the wrench body at a side opposite the shank and having its axis parallel to and spaced from the axis of the shank. An elongated wrench handle is mounted on the pivot pin and is movable with respect to the wrench body between a first position wherein the handle fits into the wrench body and is thus locked with respect to angular movement between the wrench body and the handle and a second position where it is above and spaced from the wrench body and can rotate freely about the pivot pin to cause the wrench body to rotate freely about the axis of the shank.
In the first position, the Gummow wrench does not provide any advantage over a standard fixed handle wrench when working on a nut in a confined space. In the second position, the Gummow wrench may be used to reach a nut in a confined space. However, the second position is only appropriate where the nut can be rapidly rotated under lesser load conditions.
In order to exert any significant torque in an attempt to fully tighten or loosen a nut, the user is required to apply a force along the longitudinal axis of the wrench handle while grasping the wrench handle in a bent-wrist fashion. Furthermore, it is apparent that the short moment arm of the Gummow wrench, in the second position, precludes the application of significant torque on a nut. On the other hand, the T-gripped handle of the present invention allows the user to apply significant torque to the driver by exerting force along the longitudinal axis of the extension shaft with the hand and fingers substantially parallel to the forearm in a fixed-wrist position.
Other types of tools have evolved for reducing the physical exertion on the user. For example U.S. Pat. No. 1,075,100, issued Oct. 7, 1913 to Habel, discloses a wrench having a T-shaped handle end to facilitates better grasping of the wrench during use. The handle has a permanent pivot upon which the wrench head hinges. In addition, there is no way of using the tool for article retrieval.
U.S. Pat. No. 1,568,442, issued Jan. 5, 1926 to Carver, and U.S. Pat. No. 2,068,207, issued to Torbert, Jr., disclose a wrench having an angularly positionable wrench head with respect to the handle. U.S. Pat. No. 3,882,753, issued May 13, 1975 to Svensen, discloses a wrench having an angled free turning grip for rapid tightening of threaded fasteners.
Denmark Patent Document No. 15,942, published Apr. 25, 1912, shows a hand tool having a head that pivots with respect to the handle shaft. French Patent Document No. 1,027,581, published May 13, 1953, shows a rapid-turning wrenching hand tool having a positionable handle member. German Patent Document No. 806,780, published Jun. 18, 1951, shows a rail anchor and alignment tool having a L/T-shaped extended handle for increasing turning torque. German Patent Document No. 2,823,464, published Dec. 6, 1979, shows a telescopic lever for use with a cruciform wrench for removing automobile wheel retaining nuts. These patents, likewise, have no means for article retrieval.
U.S. Pat. No. 5,474,899, issued Dec. 5, 1995 to Twomlow, discloses ratchet wrench tool having an extensible handle for increasing the length and moment arm for greater reach and torque. U.S. Pat. No. 5,860,337, issued Jan. 19, 1999 to Janssen, discloses a hand tool having an elongated handle, a pivoting end connector and a variety of interchangeable ratcheting heads. The pivoting end connector is restricted to turn within an arc of less than 180.degree.. These patents do not provide a magnet at the end of the handle for extending the users reach in retrieving dropped metal articles.
U.S. Pat. No. 5,896,606, issued Apr. 27, 1999 to Huang, discloses a hand tool having a multiplicity of features, including a magnet on a telescopic secondary shaft that extends rearwardly from within the primary tool shaft. In use the user must extend the telescopic shaft, which generally lacks integrity when fully extended. This tool also does not include a pivoting ratcheting driver head for engaging a workpiece in a confined environment.
None of the above inventions and patents, taken either singularly or in combination, is seen to describe the instant invention as claimed. Thus, a socket ratchet with a T-gripped handle extension solving the aforementioned problems is desired.